PQ Plus UMD 705, Руководство по эксплуатации

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2.2.5 Outputs and inputs
Instrument provides two separate universal I/O ports with terminals C1,D1 and C2,D2. Each
DI/O port can be used individually as an input or an output function. For a correct operation
of the I/O it is necessary to use an external power supply with nominal voltage 12 to 24 VDC.
Appropriate polarity of supply voltage for input resp. output function must be kept.
Warning !
Digital I/Os are unipolar. Right polarity must be kept for a proper operation of the terminal.
Incorrectly connected external power supply can damage the instrument.
DI/O as a digital input DI is connected to the selected I/O terminal (D1 or D2) and a common
terminal (C1 or C2) with external power supply in the following way: the current flows from
positive terminal of the supply through the external input contact to a DI terminal (D1 or D2)
and than from the common terminal (C1 or C2) back to the negative terminal of the external
power supply.
DI/O as a digital output DO is connected to the selected I/O terminal (D1 or D2) and a common
terminal (C1 or C2) with external power supply in the following way: the current flows from
positive terminal of the supply to the C1 or C2 terminal and from a DI terminal (D1 or D2)
through the controlled load to the negative terminal of the supply. If an I/O port is used as
an output (its behavior is controlled by an internal logic function) the instrument also indicates
its activation with the respective input register.
Figure 5: An example of output and inp u t of UMD 705.
digital output
digital input